There are currently several ways to measure relative angular motion in remotes and other similar devices. For example, micro electro-mechanical system (MEMS) based gyroscopes are regularly used to measure relative angular motion. These gyroscopes, however, suffer from drift errors and therefore are not ideal as absolute angle measurement devices. Another method involves utilizing a camera embedded in a remote device that measures angles by tracking external fixed light sources such as those found in gaming systems. Such a solution requires angular information to be transmitted back to the main console, TV, or computer for display and providing input to the user interface. Yet another method uses “centroid” tracking sensors using lateral photodiode(s). While all of the above systems provide measurement of angular orientation, they remain expensive for one or more of these reasons: use of MEMS, bulky lenses, or need for a communication backchannel. Thus, none of these techniques provide a precise angular measurement system that can be implemented with low-cost technology.
Hence, the inventor perceives a need in the art for an angular measurement system that may be implemented in a low cost manner. The inventor also perceives a need for a system that may be used as a controller of a host device, resembling a mouse device that can be used in free space to enter user commands to the host. Such a device may also be useful in measuring the orientation of machine parts for robotics and machine control.